Fuel injection pump



Sept. 1, 1964 G. J. KNUDSON FUEL INJECTION PUMP 2 Sheets-Sheet 1 FiledJuly 2'7, 1960 INVENTOR.

GILTNER J. KNUDSQN MMQ ATTORZEYS Sept. 1, 1964 G. J. KNU'DSON 3,146,715

' FUEL INJECTION PUMP Filed July 27, 1960 2 Sheets-Sheet 2 Fig. E

IN V EN TOR.

. "5 c! LTNER J. KNUDSON United States Patent 3,146,715 FUEL INJECTIONPUMP Giltner J. Knudsen, Santa Ana, Caliii, assignor to The BendixCorporation, Sidney, N.Y., a corporation of Deiaware Fiied July 27,196i), Ser. No. 45,621 11 Claims. c1. 103-2) This invention relates tofuel pumps of the type adapted to be utilized with internal combustionengines. The invention relates more particularly to distributor-typefuel injection pumps adapted to deliver charges of fuel under highpressure to internal combustion engines.

The invention has among its objects the provision of a new and improvedfuel pump for internal combustion engines and the like.

Another object of the invention is the provision of a fuel pump of thetype described which is relatively simple in construction and operation.

Yet another object of the invention is to provide a fuel pumpincorporating novel means for varying the amount of fuel delivered underpressure at its successive fuel injecting operations.

Still a further object of the invention is to provide a fuel pumpembodying a new and improved pumping device which may be adjusted tovary the amount of fuel injected by the pump in the successive injectingoperations thereof.

The above and further objects and novel features of the invention willmore fully appear from the following description when the same is readin connection with the accompanying drawings. It is to be expresslyunderstood, however, that the drawings are for the purpose ofillustration only, and are not intended as a definition of the limits ofthe invention.

In the drawings, wherein like reference characters refer to like partsthroughout the severalviews,

FIG. 1 is a View in longitudinal axial section through the iilustartiveembodiment of fuel pump, the parts of the pump and the controls thereforbeing shown in the posi tion which they assume when the pump is at rest,certainof the parts being shown in elevation;

FIG. 2 is a view in longitudinal axial section of the inner rotatableportion of the pump and of the inner housing part associated therewith,certain of the parts being shown in elevation;

FIG. 3 is a fragmentary view in transverse section showing the highpressure, fuel injecting pump and the generally stationary annular camassociated therewith, the section being taken along the line 33 of FIG.1, certain of the parts being shown in elevation; and

FIG. 4 is a view in section through the mechanismfor varying thetimingof the fuel injecting operations of. the pump, the section being takenalong the line 4-4 of FIG. 1, certainof the parts being shown in;elevation.

The pump of the invention is of particular advantage when employedtoinject measured quantities of fuel such as oil-directly into thecylindersof an internal combustion engine. The particular pump shown isone designed for use with a four-cylinder solid-injection diesel engine.It will be understood, however, that pumps within the scope oftheinvention are not thuslimited, and are capable of use to advantage in avariety of applications.

As shown in FIG. 1, theillustrative fuel injection pump has alongitudinally extending main shaft which extends into and is rotatablymounted within a casing gen erally designated by the character 11. Thecasing 11- is adapted to be secured to the engine through the medium ofa flange 13 on the housing, the casing being capable of limitedadjustment. about the axis of shaft 14) through the medium of arcuateslots 18 in flange 13 through which mounting studs (not shown)threadedly secured to the engine block extend. The shaft 10 is driven insynchronism with the crank shaft of the engine, in a four cycle enginebeing driven at half crank shaft speed, so as to deliver fuel charges tothe engine in the proper timed relationship.

The casing or housing 11 has a cylindrical outer portion 14 within whichis sealingly mounted a removable inner housing part 12. 0 rings 15 and16, mounted in axially spaced peripheral grooves in housing part 12,provide a seal between parts 12' and 14. Rotatably mounted within anaxially extending bore in housing part 12, and closely interfittingtherewith, is a rotatable distributor 17 in the form of anextension onshaft 10. Between the rotatable distributor. 17 and the shaft, the shaftextension is radially enlarged at 19 to provide a high pressure pumpportion, to be described.

The outer end of rotatable distributor 17 drives a low pressure ortransfer pump, generally designated 20, by means of which fuel isforwarded from a fuel source such as a tank under moderate pressure to.the high pressure, fuel-injecting pump. The transfer pump 20 includes alongitudinally extending eccentrically bored casing 21 which isnon-rotatably mounted in a bore at the outer end of easing part 12. Theouter end of rotatable member 17 is cross slotted at 22, the cross slotscarrying a first and a second slidable vane, 24 and 25, respectively,which are disposed transversely of each other. Transfer pump 26} issupplied with. fuel through an inlet fitting 26 which forms a part of acap member secured to the outer end of casing part 12 by studs, one ofwhich is shown in FIG. 2. Fuel entering at fitting 26 travels into thetransfer pump through passage 27 and after having been subjectedtopressure in such pump is discharged therefrom through a passage 29. Frompassage 29 the discharged fuel. flows under pressure through a furtherpassage 3% into an annular groove 31 which extends peripherally ofcasing part 12 and: is disposed between 0 rings 15 and 16.

Connected to annular groove 31 is a pressure relief valve 32 whichprevents the pressure of the fuel delivered by the transfer pump to thehighpressure fuel-injecting pump from exceeding a desired value. Thepressure relief valve 32, shown more particularly in FIG. 2, isconnected to annular groove 31: by means of the passages 35 and M whichlead to the pressure relief. valve proper. When the pressure of the fuelin groove 31 exceeds a predetermined value, the spring pressed ball 36is thrust from its seat, thereby allowing the escape of excess fuelthrough passage 37 in casing part 12 to an annular. groove 39 therein.From groove 39 the excess oil flows into the free'space within housing11, which is generally filled with fuel during its operation, fromwhichit is returned to the fuel tank by means not shown.

Casing part 12' is provided with four equally angularly spaced passages40, one of which is shown in FIG. 2, which lead from annular, groove 31inwardly to the central bore through part 12. Rotatable distributor 17has an annularly directed passage 41 therein, passage 41 having itsouter (right hand, FIG. 2) end connected. to the inner end of each ofpassages 40 at predetermined times during rotation of member 17, andhaving its inner (left hand) end connected at all times to the spacebetween the opposed pistons of the high pressure fuel-injectingpump, tobe described; Passage 41 is provided with a short branch passage 42intermediate its length, the outer end of branch passage 42communicating at predetermined times during the rotation of element 1 7with each of four equally angularly spaced highpressure fuel dischargepassages-44 in casing part 12. Communicating with the outer end of eachof passages 44 is a discharge fitting, 45 (one shown in FIG. 1) fromwhich conduits lead to injection nozzles connected to the respectivecylinders of the engine. As is evident in FIGS. 1 and 2, the outer endof passage 41 is closed by an imperforate portion of the wall of thebore in casing part 12 when branch passage 42 is connected to adischarge passage 44, and the outer end of branch passage 42 is closedby an imperforate Wall portion of easing part 12 when the outer end ofpassage 41 communicates with an inlet passage 40. Thus the rotatabledistributor 17 and the surrounding casing part 12 cooperating therewithfunction as a timing distributor for both the feeding of low pressurefuel from the transfer pump to the high pressure pump, and for thedischarge of fuel under high pressure from the high pressure pump.

The high pressure fuel-injecting pump, generally desi nated 46, includestwo opposed pistons 49 and ac curately fitting within a transverse bore47 in the enlarged portion 19 of the member which forms an extension ofshaft 10. The piston 49 is of completely circular cylindrical shape, andmerely reciprocates in the bore of the pump under the action of thegenerally stationary timing cam, to be described. The other piston 50not only reciprocates in the bore, but its angular position about itsaxis is controlled whereby selectively to vary the quantity of fuelinjected by the pump at each active stroke thereof. The outer end ofeach of pistons 49 and 5t! abuts the inner end of a shoe 51, the shoesbeing reciprocably mounted within guideways 52 and 53 at the right andleft hand sides, respectively, of rotatable member 19 as it is shown inFIG. 3. Each shoe 51 has a longitudinally extending part-cylindricalseat in its outer end. Within each such seat there is rotatably mounteda short longitudinally extending roller 54 which engages and rolls uponthe inner surface of a four-lobed generally stationary annular cam 55which surrounds rotatable member 19. The four lobes 56 on the innersurface of cam 55 are l0- cated 90 apart and function as member 17, 1?rotates with respect to the cam alternately to thrust the pistons 49 and50 together at the same time and to allow them to separate somewhat fromeach other under the action of centrifugal force and with the fuel fedbetween them under moderate pressure by the transverse bore.

Piston 50 is provided with a short axially extending bore 57 which isopen to the forward or inner end thereof. Communicating with the innerend of bore 57 is a trans verse bore 59 which extends outwardly to ahelically disposed slot 60 in the surface of piston 50. A spill passage61 extends longitudinally in rotatable member 19 from a zone at itsinner end generally at the location of slot 60 to a free space betweenthe inner end of shaft 11) and its extension 19, 17, whereby the fueldischarged through passage 61 is returned to the fuel sump provided bythe free space within the casing 11. The parts are so arranged that inthe initial portion of the fuel discharging stroke of piston 50, slot 60is out of communication with spill port 61, communication between slot61) and the spill port begins at a predetermined time in the operativestroke of the piston 50.

The angular position of piston 50, whereby the relationship between slot60 and spill port 61 may be varied as desired, is under the control ofthe following mechanism. A pinion 62 secured to the outer end of piston50 reciprocates therewith in the guideway 53. A longitudinallyreciprocable plunger 64 is mounted in rotatable part 19 of the pump.Plunger 64 carries a rack gear 65 on its inner face, such rack gearmeshing with pinion 62. The parts are so constructed and arranged thatpinion 62 maintains its meshing engagement with rack gear 65 despite itsreciprocation with piston 50 with respect thereto. It will be seen thatby suitable adjustment of plunger 64 piston 50 may be angularlypositioned so that the high pressure pump begins to spill at apredetermined time in its operative stroke, thereby delivering a desiredquantity of high pressure fuel at the initial portion of such stroke.

In the pump of the illustrative embodiment the position of the plunger64 is made responsive to the speed of rotation of the engine and thus ofshaft 1%. The control mechanism is so arranged that when the engine isidling at low speed the fuel charges injected by the pump are of smallvolume and that when the speed of the engine increases the volume ofsuch injected charges increases. There is thus provided in the pump aspeed responsive mechanism which governs the positioning of plunger 64.

The speed responsive mechanism includes a cage, generally designated 66,which is aflixed to and rotates With the extension 19, 17 of shaft 10.The cage includes a flanged sleeve 67, the flange portion 69 of which isaffixed to portion 19 of the shaft extension as by rivets, as shown. Thecage has a plurality of similar pocket-forming enclosure members 70within each of which there is positioned a weight 71 having a sharpouter corner 72 at the junction of its inner transverse andlongitudinally outer surfaces. Such surfaces are disposed at an angle ofsomewhat less than 90 with respect to each other so that the weightsrock about edges 72 in their respective pockets as they are subjected tovarying centrifugal force. Each of weights 71 has a radially inwardlyprojecting flange 74 which overlies an annular flange 75 on the innerend of a sleeve 76 which is keyed to shaft 10 so as to be slidabletherealong and rotatable therewith. The outer end of sleeve 76 isaffixed to the inner race of a ball bearing 77. It will be apparent thatas shaft 10 increases its speed the weights 71 are impelled to turnoutwardly around edges 72 and thus to thrust sleeve 76 axially of shaft10 with a force which bears a predetermined relationship to the speed ofrotation of the shaft.

The outer race of ball bearing 77 is affixed to a lever 79 in the formof a yoke which embraces shaft 10 and which is pivotally mounted at oneend to casing 11 by pivot pin or axle 80. The other ends of the armsforming the yoke-shaped lever 79 are connected by a cross pin 81. A coiltension spring 82 extends from cross pin 81 to a bracket rotatablysecured to the inner end of an adjusting stud 84 which extends throughand has screw threaded engagement with a portion of the housing 11 ofthe pump. The spring 82 biases lever 79 in a clockwise direction againstthe thrust imposed thereon by the weights 71 acting through sleeve 76.Spring 82 and adjusting stud 34 permit the adjustment of such biasingforce so as to adjust the idling speed of the engine.

The speed of the engine under other than idling conditions is under thecontrol of mechanism now to be described. A second yoke-like lever 85 ispivoted at one end on a pair of aligned stub shafts connected to casing11 at the opposite sides thereof. One such stub shaft is shown at 86 inFIG. 1. A cross pin 87 connects the outer or free ends of the armsmaking up the lever 85. A second coil tension spring 89 extends betweencross pin 81 of lever 79 and the cross pin 87 of lever 85. The terminalposition of lever 85 at the low speed end of the operating range of theengine is determined by the adjusted position of an adjusting stud 90which extends through and has screw threaded engagement with the housing11 at a position aligned with the outer end of lever 85. In the idle orat rest position of the pump shown in FIG. 1 the spring 89 extendssomewhat rearwardly of the longitudinal axis of lever 79, the spring 89then being in substantially its relaxed condition so that it has littleor no effect upon the adjusted idling speed of the engine. When,however, lever 85 is rotated clockwise from the position shown in FIG.1, the spring 89 exerts a biasing effect upon lever 79 which varies withthe degree of angularity of the spring 89 past the axis of lever 79. Asa consequence, the biasing force exerted upon sleeve 76 in opposition tothe force exerted thereon by weights 71 may be changed by changing theangular position of lever 85. A lever 94 positioned externally of thepump casing 11 and connected to lever 85 by one of the pivot pins 86permits lever 85 to be angularly adjusted by a throttle linkage, notshown. With lever 85 adjusted to a given position, the speed of theengine remains substantially constant regardless of changes in the loadthereon. To accomplish this result, weights 71 cause a shifting ofsleeve '36 thereby to adjust plunger 64 and the spill ports 60, 61 ofpiston 50 so as to maintain the engine at the desired speed. The pumpalso includes an externally mounted lever 95, connected to pivot shaft80 of lever 79, whereby the latter shaft may be turned so that the slot60 of piston 59 remains in communication with spill port 61 throughoutthe entire stroke of piston 50. When lever 79. is thus moved, thedelivery of fuel under high pressure to the engine is cut off, and theengine stops.

The pump shown also includes means whereby the timing of the injectionstrokes of the high pressure pump 46 is automatically changed inresponse to changes in the speed of rotation of the engine. A timingcontrol arm 96 extends radially from an edge portion of the annular cam55 and outwardly through a slot in pump housing 11 which permits the camand its attached arm to rotate about the axis of the cam through a smallangle. The outer end of arm 96 carires a rounded knob 97 which isoperatively connected to. a hollow piston 102 reciprocably mountedwithin a bore 101 in a. sub-housing 99 affixed to casing 11. by a stud100. As shown in FIG. 4, the knob 9.7 on arm 96, is held between a seat104 on the inner end surface of the hollow piston -2 and a coilcompression spring 105, the outer end of which abuts a plug member 106which closes the end of the bore in housing 99.

Fuel under transfer pump pressure in annular groove 31 is led throughangular passage 107 (FIG. 1) to an annular space 109 surrounding thestud 100 (FIG. 4). Frompassage 109 the fuel travels through passage 110through a one-way valve 11 and thence through a further passage 112 intobore 101 at the location of. a longitudinal groove 114 in piston 102.Fuel flows to the right through groove 114. into the space 115 betweenthe outer end of thepiston and the cylinder.

The pressure of the fuel delivered by the transfer pump varies generallyin accordance with the speed of the transfer pump and thus of. theengine. Accordingly, as the speed of the engine increases the pressureof the fuel in space 115 increases, thereby thrusting piston 102 to theleft (FIG. 4) to advance the timing of the operative fuel injectingstrokes of the pump 46. The coil compression spring 105 maintains knob97' in contact with seat 104, tand rotatescam 55 through. arm 96 in aretarding direction when the speed of the engine decreases.

Although only one embodiment of the invention has been illustrated inthe accompanying drawings and described in the foregoing specification,it is to be especially understood that various changes, such as in therelative dimensions of the parts, materials used, and the like, as wellas the suggested manner of use of the apparatus of the invention, may bemade therein without departing from the spirit and scope of theinvention as will now be apparent to those skilled in the art.

What is claimed is:

1. In a device of the character described, a housing having alongitudinal bore, a rotor mounted for rotation in said longitudialbore, said rotor having a pumping portion and a distributing portionwhereby fuel pumped by said pumping portion will be delivered to saiddistributing portion, said distributing portion being adapted tocommunicate with a plurality of outlets successively upon rotation ofsaid rotor, said pumping portion of said rotor having a radial bore, aplunger mounted for reciprocation in said radial bore, cam meansadjacent the periphery of said pumping portion for effecting the pumpingstroke of said plunger upon rotation of said rotor, said plunger havingfuel spill control means, and means operable while the rotor is rotatingfor effecting rotation of said plunger to thereby adjust said fuel spillcontrol means, whereby the quantity of fuel delivered by said 6 pumpingportion to said distributing portion may be varied.

2. In a device of the character described, a housing having alongitudinal bore, a rotor mounted for rotation in said longitudinalbore, said rotor having a pumping portion and a distributing portionwhereby fuel pumped by said pumping portion will be delivered to saiddistributing portion, said distributing portion being adapted. to,communicate with a plurality of outlets successively upon rotation ofsaid rotor, said pumping portion of said rotor having a radial bore, aplunger mounted for reciprocation in said radial bore, cam meansadjacent the periphery of said pumping portion for effecting the pumpingstroke of said plunger upon, rotation of said rotor, said plunger havingfuel spill control means, and means operable while the rotor is rotatingfor effecting rotation of said plunger to thereby adjust said fuel spillcontrol means, said fuel spill control means comprising a slot in saidplunger and a fuel spill port adapted to communicate with said slot.

3. In a device of the character described, a housing having alongitudinal bore, a rotor mounted for rotation in said longitudinalbore, said rotor having a pumping portion and 'a distributing portionwhereby fuel pumped by said pumping portion will be delivered to saiddistributing portion, said distributing portion being adapted tocommunicate with a plurality of outlets successively upon rotation ofsaid rotor, said pumping portion of said rotor having a radial bore, aplunger mounted for reciprocation in said radial bore, cam meansadjacent the periphery of said pumping portion for effecting the pumpingstroke of said plunger upon rotation of said rotor, said plunger havingfuel spill control means, and means operable while the rotor is rotatingfor effecting rotation of said plunger to thereby adjust said fuel spillcontrol means, said fuel spill control means comprising a helical slotin said plunger and a fuel spill port adapted to communicate with saidslot.

4. In a device of the character described, a housing having alongitudinal bore, a rotor mounted for rotation in said longitudinalbore, said rotor having a pumping portion and a distributing portionwhereby fuel pumped by said pumping portion will be delivered to saiddistributing portion, said distributing portion being adapted tocommunicate with a plurality of outlets successively upon rotation ofsaid rotor, said pumping portion of said rotor having a radial bore, aplunger mounted for reciprocation in said radial bore, cam meansadjacent, the periphery of said pumping portion for efi'ecting thepumping stroke of said plunger upon rotation of said rotor, said plungerhaving fuel spill control means, and means on said rotor operable whilethe rotor is rotating, for effecting rotation of said plunger to therebyadjust said fuel spill control means.

5. In a device of the character described, a housing having alongitudinal bore, a rotor mounted for rotation in said longitudinalbore, said rotor having a pumping portion and a distributing portion incommunication with said pumping portion, whereby fuel pumped by saidpumping portion will be delivered to said distributing portion, saiddistributing portion being adapted to distribute fuel pumped by saidpumping portion to each of a plurality of outlets successively uponrotation of said rotor, said pumping portion having a radial bore,opposed plungers mounted for reciprocation in said radial bore, cammeans adjacent the periphery of said pumping portion for effecting thepumping stroke of said plungers upon relative rotation of said rotor andcam means, one of said plungers having fuel spill control means, andmeans for rotating said one plunger to adjust said fuel spill controlmeans, said means for rotating said plunger comprising means on saidrotor movable 1ongitudinally thereof while the rotor is rotating, andmeans operatively connecting said movable means and said plunger,whereby upon movement of said movable means said plunger will be rotatedto thereby eifect adjustment of said fuel spill control means.

6. A device as claimed in claim 5, wherein the movable means is anannular member on the rotor, the annular member being slidable along therotor and rotatable therewith.

7. A device as claimed in claim 6, comprising a further means movablealong the rotor and having thrusting relationship with the annularmember, and means for holding the further means from rotation with therotor and for adjusting the further means and thus the annular memberlongitudinally of the rotor.

8. In a device of the character described, a housing having alongitudinal bore, a rotor mounted for rotation in said longitudinalbore, said rotor having a pumping portion and a distributing portion incommunication with said pumping portion, whereby fuel pumped by saidpumping portion will be delivered to said distributing portion, saiddistributing portion being adapted to distribute fuel pumped by saidpumping portion to each of a plurality of outlets successively uponrotation of said rotor, said pumping portion having a radial bore,opposed plungers mounted for reciprocation in said radial bore, cammeans adjacent the periphery of said pumping portion for effecting thepumping stroke of said plungers upon relative rotation of said rotor andcam means, one of said plungers having fuel spill control means, andmeans for rotating said one plunger to adjust said fuel spill controlmeans, said means for rotating said plunger comprising means on saidrotor movable longitudinally thereof while the rotor is rotating, and arack operatively connected to said movable means and engaging saidplunger, whereby upon movement of said rack by said movable means saidplunger will be rotated to thereby effect adjustment of said fuel spillcontrol means.

9. In a device of the character described, a housing having alongitudinal bore, a rotor mounted for rotation in said longitudinalbore, said rotor having a pumping portion and a distributing portionwhereby fuel pumped by said pumping portion will be delivered to saiddistributing portion, said distributing portion being adapted tocommunicate with a plurality of outlets successively upon rotation ofsaid rotor, said pumping portion of said rotor having a radial bore, aplunger mounted for recipro cation in said radial bore, cam meansadjacent the periphery of said pumping portion for effecting the pumpingstroke of said plunger upon rotation of said rotor, said plunger havingfuel spill control means and means actuated upon rotation of said rotorfor effecting rotation of said plunger to thereby adjust said fuel spillcontrol means, and means on said rotor for actuating said means forrotating said plunger upon rotation of said rotor.

10. In a device of the character described, a housing having alongitudinal bore, a rotor mounted for rotation in said longitudinalbore, said rotor having a pumping portion and a distributing portionwhereby fuel pumped by said pumping portion will be delivered to saiddistributing portion, said distributing portion being adapted tocommunicate with a plurality of outlets successively upon rotation ofsaid rotor, said pumping portion of said rotor having a radial bore, aplunger mounted for reciprocation in said radial bore, cam meansadjacent the periphery of said pumping portion for effecting the pumpingstroke of said plunger upon rotation of said rotor, said plunger havingfuel spill control means and means actuated upon rotation of said rotorfor effecting rotation of said plunger thereby to adjust said fuel spillcontrol means, said fuel spill control means comprising a slot in saidplunger and a fuel spill port adapted to communicate with said slot, theslot in the plunger and the fuel spill port being so disposed that thefuel spill means becomes operative only at the end portion of the pumping stroke of the plunger.

11. In a device of the character described, a housing having alongitudinal bore, a rotor mounted for rotation in said longitudinalbore, said rotor having a pumping portion and a distributing portionwhereby fuel pumped by said pumping portion will be delivered to saiddistributing portion, said distributing portion being adapted tocommunicate with a plurality of outlets successively upon rotation ofsaid rotor, said pumping portion of said rotor having a radial bore, aplunger mounted for reciprocation in said radial bore, cam meansadjacent the periphery of said pumping portion for effecting the pumpingstroke of said plunger upon rotation of said rotor, said plunger havingfuel spill control means and means actuated upon rotation of said rotorfor effecting rotation of said plunger to thereby adjust said fuel spillcontrol means, said fuel spill control means comprising a helical slotin said plunger and a fuel spill port adapted to communicate with saidslot, the slot in the plunger and the fuel spill port being so disposedthat the fuel spill means becomes operative only at the end portion ofthe pumping stroke of the plunger.

References Cited in the file of this patent UNITED STATES PATENTS2,922,370 Bischoif Jan. 26, 1960

1. IN A DEVICE OF THE CHARACTER DESCRIBED, A HOUSING HAVING ALONGITUDINAL BORE, A ROTOR MOUNTED FOR ROTATION IN SAID LONGITUDINALBORE, A ROTOR HAVING A PUMPING PORTION AND A DISTRIBUTING PORTIONWHEREBY FUEL PUMPED BY SAID PUMPING PORTION WILL BE DELIVERED TO SAIDDISTRIBUTING PORTION, SAID DISTRIBUTING PORTION BEING ADAPTED TOCOMMUNICATE WITH A PLURALITY OF OUTLETS SUCCESSIVELY UPON ROTATION OFSAID ROTOR, SAID PUMPING PORTION OF SAID ROTOR HAVING A RADIAL BORE, APLUNGER MOUNTED FOR RECIPROCATION IN SAID RADIAL BORE, CAM MEANSADJACENT THE PERIPHERY OF SAID PUMPING PORTION FOR EFFECTING THE PUMP-